Please try rdmd on large projects

[Juan Manuel Cabo]

Doing:

  ltrace -e open dmd -deps=outdeps.txt example.d

and:

  ltrace -e read dmd -deps=outdeps.txt example.d

shows that dmd opens and reads a lot of phobos and druntime
to generate the dependencies of:

     import std.stdio;
     void main() { writeln("something");}

--jm


On 02/21/2012 02:02 AM, Juan Manuel Cabo wrote:
> GOOD!
> 
> Is the missing chmod problem fixable? So that the
> binary has the same permissions as the D file?
> If my D file is not readable or runnable by 'other',
> the binary shouldn't be either. (the cached .deps should
> have the same readability as the D file too perhaps).
> 
> 
> I think that this is the big timesaver:
> 
>      rdmd: cache dependency file to improve startup time
> 
> So: Big Thanks!! I was using a wrapper for rdmd that only
> called rdmd if the file was modified (which worked great for
> small one file scripts, those 300ms to 1000ms startup
> delays where unbearable).
> With the .deps caching, rerun time went down to 20ms.
> It was 300ms ~ 1000ms before (depending on how many imports).
> 
> I think that 20ms is still too slow (for certain applications,
> it is just too much).
> 
> When rdmd asks dmd to generate the dependencies of my_file.d,
> dmd goes beyond and parses phobos files, opening
> all the module files in the path of dependency. I think
> that was the major slow part.
> 
> Is it possible to have an option to skip rechecking inside phobos
> dependencies each time? That would be the thing that brings
> it down to < 5ms.
> 
> --jm
> 
> 
> On 02/20/2012 07:17 PM, Andrei Alexandrescu wrote:
>> Hello,
>>
>>
>> I just submitted (https://github.com/D-Programming-Language/tools/commit/c77b870fdc5674d7434b03d1767ba831eaac25b1) a
>> change to rdmd that runs one thread per stat when comparing file dates, using David's excellent std.parallelism.
>>
>> In my experiment the change introduces no additional lag on small projects and works 10-15% faster on moderate projects
>> (couple dozen deps).
>>
>> Could someone try rdmd against some larger projects and assess its behavior and speed?
>>
>>
>> Thanks,
>>
>> Andrei
>